The current problem of water pollution is sufficiently well known that a discussion herein would be superflous.
However, we are currently faced with statutes requiring both the immediate improvement in existing waste water systems and the pretreatment of industrial or agricultural effluents before the effluent reaches such overloaded treatment facilities.
In most cases, extreme difficulties are encountered in trying to expand or upgrade sewage treatment plants. Either additional land is not available or additional, major funds are not available -- or both are impossible to obtain at all or in the time period required.
Industrial and agricultural enterprises, in many cases, cannot justify the costs of known fixed-treatment units alternatively, they are penalized for delivery of excessive waste concentrations.